Recent advances in the role of interleukin-6 in health and disease.

Interleukin-6 (IL-6) is a pleotropic cytokine, and in this review, we highlight recent studies focusing on the role of IL-6 in health and disease. IL-6 is known as an exercise-inducible myokine, and in rodents it was identified that a lactate-dependent increase in protease activity mediates IL-6 release from skeletal muscle, which acts in both an autocrine and paracrine roles. In humans, a series of publications observed that blocking IL-6 during exercise training prevented beneficial adaptations, such as reductions in visceral and epicardial fat mass. Independent of exercise, IL-6 impacts postprandial physiology, as demonstrated by a slowing of gastric emptying rate and improving glucose homeostasis. Finally, an engineered cytokine harnessing the biology of IL-6, termed IC7Fc, was found to have beneficial impacts on numerous health outcomes. Together, these recent advances indicate that IL-6 has a multifaceted, and perhaps beneficial, role in health and disease.